Memory devices are typically provided as internal, semiconductor, integrated circuits in computers or other electronic devices. There are many different types of memory including volatile and non-volatile memory. Volatile memory can require power to maintain its data and includes random-access memory (RAM), dynamic random access memory (DRAM), and synchronous dynamic random access memory (SDRAM), among others. Non-volatile memory can provide persistent data by retaining stored data when not powered and can include NAND flash memory, NOR flash memory, read only memory (ROM), Electrically Erasable Programmable ROM (EEPROM), Erasable Programmable ROM (EPROM), and resistance variable memory such as phase change random access memory (PCRAM), resistive random access memory (RRAM), and magnetoresistive random access memory (MRAM), among others.
Memory devices can be combined together to form a storage volume of a memory system such as a solid state drive (SSD). A solid state drive can include non-volatile memory (e.g., NAND flash memory and NOR flash memory), and/or can include volatile memory (e.g., DRAM and SRAM), among various other types of non-volatile and volatile memory.
In various instances, a single level memory cell (SLC) can refer to a cell programmed to a targeted one of two different data states and configured to store a single data unit (e.g., one bit). Some memory cells (e.g., Flash cells, phase change cells, etc.) can be programmed to a targeted one of more than two different data states such that they are configured to store more than a single data unit (e.g., 2 bits, 2.5 bits, 3 bits, 4 bits, etc.). Such cells may be referred to as multi state memory cells, multiunit cells, multilevel cells, or extra level cells (XLCs). XLCs can provide higher density memories without increasing the number of memory cells since each cell can represent more than one data unit.
Various memory cells experience wear over time due to programming and/or erase cycling, for instance. Memory devices comprising such memory cells can have device specifications such as a total bytes written (TBW) specification and/or a cycle count (e.g., erase count and/or program count) specification, for example, used to gauge a device's health and/or useful life. Some memory cells are capable of being operated (e.g., programed, read, erased, etc.) in both an SLC mode and an XLC mode (e.g., 2-bit “MLC” mode, 3-bit “TLC” mode, 4-bit “QLC” mode, etc.). Such cells can be referred to as “mixed mode” memory cells.
Programming XLC cells can include a data entry phase and a programming phase. The data, such as pages of data, associated with each bit of XLC cells can be entered into a buffer to be programmed to the XLC cells. A period of time can be used to transfer the data to the buffer. The programming of the XLC cells can take a period of time and be delayed by waiting for the data to be entered into the buffer for programming.